Aluminum member and method for producing same

Abstract

An aluminum member includes: a substrate formed of aluminum or an aluminum alloy that contains 0 to 10% by mass of magnesium, 0.1% by mass or less of iron, and 0.1% by mass or less of silicon and a balance of which is aluminum and unavoidable impurities; and an anodic oxide coating formed on a surface of the substrate. A surface of the substrate on the anodic oxide coating side has an arithmetical mean height Sa of 0.1 to 0.5 μm, a maximum height Sz of 0.2 to 5 μm, and an mean width of roughness profile elements Rsm of 0.5 to 10 μm, where the arithmetical mean height Sa, the maximum height Sz, and the mean width of roughness profile elements Rsm are measured after the anodic oxide coating is removed.

The invention claimed is: 
     
       1. A method of producing an aluminum member comprising a substrate and an anodic oxide coating comprising
 making particles having an average particle diameter of 20 μm or less hit against a surface of the substrate by dry blasting; 
 etching the substrate against which the particles have hit, using at least one of an acidic solution and an alkaline solution; and 
 forming the anodic oxide coating by anodizing an etched surface of the substrate, 
 wherein the substrate is formed of aluminum or an aluminum alloy that contains 0 to 10% by mass of magnesium, 0.1% by mass or less of iron, and 0.1% by mass or less of silicon and a balance of which is aluminum and unavoidable impurities, 
 wherein the anodic oxide coating is formed on the surface of the substrate, and 
 wherein the surface of the substrate on the anodic oxide coating side has an arithmetical mean height Sa of 0.1 to 0.5 μm, a maximum height Sz of 0.2 to 5 μm, and an mean width of roughness profile elements Rsm of 0.5 to 10 μm, where the arithmetical mean height Sa, the maximum height Sz, and the mean width of roughness profile elements Rsm are measured in a case where the anodic oxide coating is removed. 
 
     
     
       2. The method of producing the aluminum member according to  claim 1 , wherein
 the substrate consists of 0 to 10% by mass of magnesium, 0.1% by mass or less of iron, and 0.1% by mass or less of silicon and the balance of which is aluminum and 0.5% by mass or less of unavoidable impurities, 
 and a content of each element contained as the unavoidable impurities is 0.05% by mass or less. 
 
     
     
       3. The method of producing the aluminum member according to  claim 1 , wherein
 the substrate consists of 0 to 10% by mass of magnesium, 0.1% by mass or less of iron, and 0.1% by mass or less of silicon and the balance of which is aluminum and 0.15% by mass or less of unavoidable impurities, 
 and a content of each element contained as the unavoidable impurities is 0.05% by mass or less. 
 
     
     
       4. The method of producing the aluminum member according to  claim 1 , wherein the anodic oxide coating is formed by using at least one aqueous solution selected from the group consisting of sulfuric acid, phosphoric acid, and oxalic acid. 
     
     
       5. The method of producing the aluminum member according to  claim 1 , wherein a time of the etching is 5 to 90 seconds. 
     
     
       6. The method of producing the aluminum member according to  claim 1 , wherein
 the aluminum member has an L* value of 85 to 100, an a* value of −1 to +1, and a b* value of −1.5 to +1.5, where the L* value, the a* value, and the b* value are values in a L*a*b* color system measured from the anodic oxide coating side. 
 
     
     
       7. The method of producing the aluminum member according to  claim 1 , wherein
 a surface of the anodic oxide coating has an arithmetical mean height Sa of 0 to 0.45 μm, and the L* value is 85.5 to 100. 
 
     
     
       8. The method of producing the aluminum member according to  claim 1 , further comprising
 polishing a surface of the anodic oxide coating by at least one of blast polishing and buff polishing.